Undescribable
by CaroNovo
Summary: When Levi is tasked to follow a human kid around and find everything he can about the key hanging around his neck he definitely isn't happy. But the one time he loses sight of Eren, he finally finds him fighting off 6 guys with speed and strength he shouldn't possess, all while his eyes are glowing gold, and this will change everything. Vampire!Levi and Hybrid!Eren


Levi hated Erwin. Of course, this was nothing new, but in this very moment he felt it more strongly than what was common. He was hiding behind trees, covered in the shadows like some sort of creep, watching as his target walked home with his two companions.

Eren Jaeger, 21. Student at Trost University. Son of Grisha Jaeger and an unknown woman. Human.

This was the information given to Levi after Erwin ordered him to follow the kid around, learn about him, and find any valuable information about the key hanging around his neck. He didn't know why Erwin was so interested in the key; truth be told, he rarely knew why Erwin was interested in anything, but he was the Commander of the Survey Corps and Levi wasn't going to start doubting his judgment now. This didn't stop him from insulting the man a thousand times over in his head, though.

He kept walking behind the trees, making sure not to lose visual contact on the kid walking parallel on the sidewalk about 80 meters away. Even with his heightened hearing he couldn't make out what the trio was saying. Not that he really wanted to, but anything they said could contain valuable information for the mission, so he inched a little closer, still hidden from view, and strained his ears.

"–nd just because you didn't hear the professor explain the assignment doesn't mean you don't have to do it. You can't keep falling asleep in class, Eren!" Blondie sounded slightly exasperated.

What Levi had learned over the past 2 weeks or so was that Blondie was a studious motherfucker. Every time he would listen in on their conversations he was talking about his classes, his books, or rambling on and on about whatever was holding his interest at the time. He didn't know how the other two could handle this every day; but then again, he was friends with Shitty Glasses, so he should know.

Not that he would ever admit this out loud.

"But his class is fucking boring. He is literally trying to prove to the scientific community that a person can die of extreme boredom if you just talk for a couple of hours about logarithms and imaginary numbers. And he will, prove it I mean, because I'm already feeling the presence of Death near me, and let me tell you, it wasn't there before his class."

He had also learned that his target was a little shit. He hadn't expected otherwise, but he had to admit he was a little impressed by his ability to exaggerate and overreact to almost every possible scenario.

"You're exaggerating, Eren. If you're having a difficult time understanding the class you can ask Armin or me. You know we would help you if you asked." The third companion said.

"It's not that I don't understand his class, it's that I don't like it." Eren sighed before continuing, "Look, I appreciate the offer but it isn't something you need to worry about."

Levi knew that, like every other time, this conversation wasn't going to give him any clues about the key, so he decided to call it a day and head back to his apartment. He turned around and started walking before taking out his cellphone and dialing his second in command. It only took two rings before he answered.

"Hello?" Said the voice at the other end of the line.

"Eld, you're up. I'm fucking tired of following him around and listening to his pointless conversations."

He hung up before he got an answer and made his way home. Home being a small apartment the Survey Corps had rented for him in order to get close to where the kid lived and make it easier to follow him around. The rest of his squad had to share apartment with another of the team members, but being the leader had its perks.

As was usual, he decided to spend his free time cleaning up, even though he had done the same thing yesterday. He took out his cleaning supplies and started with dusting every surface on the living room.

As he worked, his mind wandered off to the key and what it meant. He had thought it would be something important, and that the kid and his friends would mention it from time to time, or maybe go to the place the key opened, but none of that had happened. Right now the key didn't seem like anything other than ordinary and mundane and it was starting to get annoying. But even if the key itself wasn't all that interesting, there was something else that was: its carrier.

Eren Jaeger was the most stubborn and impulsive person he had ever met. He had no brain-to-mouth filter and acted before thinking, even when the situation wasn't favorable; and still, his actions and reasoning were easy to understand. He was passionate and dedicated to everything he did and his eyes, those freakishly bright eyes, would change color depending on what he was feeling. The guy was an open book, and while this typically suggested innocence or naivety, Levi knew he was none of that.

He didn't know if Eren was aware that his father was one of the oldest vampires in the world. The kid didn't seem to know anything about the supernatural, just like every other human, but the circumstances of his birth and childhood were different than most.

A vampire couple can have children, but these children aren't guaranteed to be born as vampires. In fact, most vampire offspring are born human, and when they're old enough to withstand the changing and give their consent, they will be turned. Most families are made up entirely of vampires; nobody wants to be a vampire and deal with a human child, but there are some rare ones, like Eren's, that decide to let the kid live a normal human life, even if their parents are anything but that.

Human children are also a problem because of the aging. An original-born vampire will grow up like a human until they drain someone of their blood, but leave enough of it in their system so that they can survive. A human-born vampire is turned when they give their approval, typically when they have fully grown and are considered adults in society. Whatever the case, once either process is completed the person will stop aging. This is the reason most parents encourage their children to become vampires once they're ready; nobody wants to see their own blood grow old and die, while you are fated to live forever.

But Eren is a strange case. He clearly is the offspring of vampires and was obviously born human, but his mother doesn't appear to be in the picture. No matter how many records and documents they went through, they couldn't find any evidence of her existence in their system; so it is safe to assume that Grisha raised him by himself. The problem with this is that Grisha disappeared 9 years ago, when Eren would have been 12. If Grisha wanted Eren to grow up as a human, he might have kept his identity a secret, and Eren would have no way of finding out the truth. He might not be aware that his parents weren't humans, but vampires.

Levi thought that this could be the reason why Grisha had left him the key; so that he could find the truth about his parents. But then why would Erwin be so interested in it? What is he fucking thinking?

His thoughts went on like this; trying to understand why Eren and the key were so important, why Grisha had disappeared, how it was all connected to The Order, and then giving up in trying to comprehend Erwin and what he was planning, just to start over again from the beginning.

Before he knew it, he had finished cleaning his apartment and was no closer to figuring out what the fuck was going on. He looked through his window and notice that the sun was beginning to descend, although it would still be a couple of hours before it would set.

His phone rang as he was putting away his cleaning supplies, and he answered after confirming it was Eld calling.

"Yes?"

"Levi, my shift is about to be over. The kids have been eating and watching movies all day, although the blonde one, Armin, left about 5 minutes ago. Mikasa is still there, though"

"I won't be long. I doubt anything important will happen in the next 5 minutes so just go home." Levi said before adding, "Did they mention anything about the key?"

"Not a word." Levi clicked his tongue. He was really getting annoyed about following them every day and coming up empty handed.

"I'll see you tomorrow." He ended the call and grabbed a coat before heading outside. It was autumn, and even if right now the temperature was nice, he knew once the sun set the cold would be a bitch.

He made his way to the brat's building and scowled when he noticed his feet moving automatically, now used to walking this path thanks to the constant need of taking it while following the kid. As he got closer he knew something was off. Eld had said that they were watching movies, but the lights corresponding to his apartment were off. Levi knew it couldn't be more than 5 minutes since he'd talked with Eld so where the hell were they?

He concentrated his hearing and after a moment he could make out the faint sounds of two people running down the street. He followed the sounds; confident that they belonged to the people he was looking for. He decided to walk fast instead of run, because even though he wanted to get there fast, it could bring unwanted attention and that was the last thing he needed. Levi came to a halt when the footsteps were cut short and listened again, trying to pinpoint the location of where they'd stopped. He heard a single pair of footsteps down an alley about 100 meters away from him, and as he got closer he started to hear the unmistakable sounds of a fight. He could hear steps, and grunts, and punches, and he hurried his step in case the brat and his friend were on the losing side. It would be fucking stupid if their main information source about the key was beaten to death.

What he saw when he quietly entered the alley was not what he expected.

The narrow space was hidden in shadows casted by the setting sun, but they did nothing to conceal the scene happening in front of Levi's eyes.

Mikasa was kneeling in front of a bloody Armin, trying to check if he had been critically injured while he assured her that he was fine. 6 thugs took up the rest of the space in the alley, and in the middle of them was Eren Jaeger. Eren Jaeger, who he had been watching for 2 weeks and discovered nothing bizarre about; Eren Jaeger, who he had seen get into fights but was quickly separated by his friends; Eren Jaeger, who had fucking bright, undefinable eyes that hid nothing.

Eren Jaeger, whose eyes now shone a brilliant gold; Eren Jaeger, who was beating up 6 guys twice his size and triple his weight; Eren Jaeger, who looked like an unstoppable force of blurred kicks and punches.

Eren Jaeger, who possessed speed and strength he shouldn't have.

Shit.

They had been wrong.

Eren Jaeger was not human.


End file.
